Answer
(a) $k = 0.000045 N·m^2$
(b) $F = 0.000005 N$
(c) Refer to the graph below
Work Step by Step
(a) $F = 0.0005N$, $x = 0.3m$
$F = \frac{k}{x^2}$ so $0.0005 = \frac{k}{(0.3)^2}$ and $k = 0.000045 N·m^2$
(b) $x = 3m$, $k = 0.000045N.m^2$
$F = \frac{0.000045}{3^2} = 0.000005N$
(c) Refer to the graph above
